Wireless digital networks provide users secure and cost-effective access to resources. Such wireless digital networks typically have a plurality of access points (AP) located throughout a designated area, by which the users can access the resources they desire. Wi-Fi networks operating in accordance with IEEE 802.11 standards are examples of such networks. The frequencies used by these networks are shared. They are shared not only among the wireless digital networks themselves, but also with other non-network devices. These shared frequencies face intermittent and continuous interference received from other non-network devices, including radio-frequency devices, such as microwave ovens, wireless video streaming devices, cordless telephones, and the like, as well as other adjacent wireless networking devices. Unfortunately, the effects of these types of interfering devices can vary. As an example, simply replacing or adding a microwave oven in a particular area where a particular wireless digital network is operating can dramatically alter the interference levels present within that particular wireless digital network.
To identify the sources of interference that obstruct operation of a wireless digital network, various types of test equipment and functionalities are used, for example, spectrum analyzers. Although sophisticated spectrum analyzers exist, which include receivers that may be calibrated to display and measure signals over a wide range of frequencies and amplitudes, such sophisticated devices are costly and often not used for continuous monitoring and management of wireless digital networks. Wireless digital networks contain access points (AP) and wireless client devices, both examples of narrowband network (radio) devices with scanning functionality.
Each radio device (e.g., access point) periodically scans the frequency spectrum to detect and identify potential interference. The frequency spectrum is a frequency range that is divided into multiple channels. The time required to scan the entire frequency spectrum is proportional to the number of channels that are scanned and the type of information that needs to be collected. Hence, considerable time can lapse before a radio device (access point) can scan the same channel again. Frequent scanning of channels is critical to yield updated channel information, which is used to detect and identify wireless interference.
As a related consideration, many network devices, for example, access points (APs) support variable frequency channel widths, including for example, 20 MHz, 40 MHz and 80 MHz channels. They may also support 160 MHz or other channel widths. Existing systems and methods for scanning frequency spectrums are limited to scanning of fixed-width frequency channels or a predetermined sequence of channels
A typical spectrum analyzer configured to use these fixed-width or narrowband radio frequencies may need to collect information such as wireless frames in compliance with IEEE 802.11 standards, spectral analysis FFT (Fast Fourier Transform) plots, noise floor, and channel utilization (Tx and Rx) on various channels. Spectrum analysis also requires that information on a wideband frequency spectrum (for example, the entire 2.4 GHz or 5 GHz band) be collected at fixed-time intervals (for example, ranging anywhere from 500 milliseconds to 2 seconds). These fixed-time intervals dictate the amount of time to be spent in search of interference activity or “dwell” time on each channel. It is virtually impossible to scan all possible channels and channel widths within the fixed-time intervals or dwell times that are typically allocated for scanning of channels.
Moreover, other information such as noise floor and channel utilization may depend on the width of the selected channel, depending on the activities on parts of the channel and due to implementation constraints of the network devices themselves.
Therefore, it is desirable to have enhanced ways for scanning frequency spectrums effectively and efficiently to capture wideband spectrum data to accurately detect and identify interference in wireless digital networks. It is also desirable to have enhanced ways to report channel status, such as noise floor, Wi-Fi and non-Wi-Fi channel utilization, ACI, number and types of Wi-Fi, and non-Wi-Fi devices.